The present invention provides a method for displaying a set of numerical data graphically on an Internet web page by creating a pie chart having “slices”, each of which is proportional in size to the value of one datum.
More specifically the present invention teaches a method for affixing to a web page instructions for displaying numerical data in pie chart form and for updating the pie chart display in response to changes in the data.
The use of pie charts to make data comparisons is a technique known in the art. Long before the birth of personal computers and of the Internet, pie charts were drawn on paper, blackboards, and the like in order to enable an audience to readily compare numerically measurable attributes such as dollar expenditures and revenues, population distributions, and the like.
In a client-server environment in which the client communicates with the server over the Internet, it has been known to enable the client to transmit data entered on a web page to the server, and to receive back from the server instructions for drawing a pie chart representative of the data on the web page. However, when the client is working offline, i.e., disconnected from the server, the generation of a pie chart to illustrate the data on the web page in an efficient manner has not been possible.
Pie charts are made up of “slices” each of which represents one datum. Each slice has a circular or elliptical arc and two radii connecting the ends of the arc with the center of the circle or ellipse.
Web browsers typically deal with rectangular elements. Web technologies (HTML, CSS) do not provide built-in methods for creating non-rectangular shapes such as pie slices.